Grounded Value

In recent weeks, I’ve spent a good bit of time speaking to landscaping colleagues, garden clubs and symposium attendees about our general need to get smarter when it comes to how we think about landscapes. This is all part of my perpetual campaign to convince everyone to use the right plants in the right places in order to save water, labor and the fuels consumed in maintaining them.

A big part of my pitch is one I’ve addressed before in this space – that is, I object to installing large expanses of lawn just for the sake of having them.

Some landscaping professionals don’t like it when I speak up or write about this, basically because many of them make good money mowing lawns. But all I can say about a client’s desire for grass is, why? Then I let them know that, if they want theirs to be healthy and golf-course green, lawns require vast amounts of water, care, fertilization, pesticide application and mowing.

In my book, that makes them undesirably costly, environmentally suspect, energy inefficient and hard to rationalize. And besides, there are so many good alternatives!

OFF THE GRASS

Every spring (including this one so far), I receive innumerable calls from clients and prospects who want us to come out and revitalize lawns that suffered through a rough winter. In almost all cases, the areas they’re most concerned about are beneath the canopies of large, mature trees, including maples, oaks and lindens.

Every spring (again including this one so far), I become a broken record, repeatedly saying, “No, you can’t grow grass in this situation.” Almost invariably, they come back at me with words to the following effect: “But when I seeded last spring, the lawn came in and looked great – then it withered in the summer.”

The reason for this, I tell them, is dirt simple: Grass is a full-sun plant and does not fare well in shade. In addition, it competes for water with the mature trees, and a lawn will lose that battle every time.

This is why I get so agitated with many of my colleagues, who will go out in spring, tear out clients’ lawns, top-dress the space with nice soil and then seed or sod the area. It’ll all look absolutely great when the client signs the check, but by summer, areas under tree canopies will have begun showing signs of stress. I can’t fault the homeowner for not knowing this will happen, but I do fault professionals who either don’t know any better (but should) or do know full well what will happen and take their clients’ money anyway.

That’s one of the reasons why I spend so much time speaking to groups of homeowners as well as professionals: My Big Idea, oft repeated, is that grass should not be planted in these situations, that there are better ways to deal with these spaces, and that the options require less maintenance, less water and are, quite frankly, easier on the eye.

Japanese Primrose is a wonderful and under-used perennial that serves well as a groundcover. It can handle full shade and very wet sites – and combines beautifully with Astilbe (seen in the photograph on this column’s opening page) and Hakonechloa (seen on page XX) to brighten up darker areas.

This is when I start pressing everyone to think about groundcovers and the huge range of possibilities my audiences – professional and civilian – have to make better, more efficient use of available, shaded spaces.

Here in the northeast, for example, evergreen groundcovers such as Myrtle (also known as Vinca) and Pachysandra are quite popular and reliable and do very well in shade. These are typically planted as rooted cuttings at intervals of about eight inches on center and will spread and completely fill in an area in about two years – if, of course, the soil has been prepared properly.

Both of these groundcovers (along with the less-used Wintercreeper, a groundcover version of Euonymus) are, as I mentioned, evergreen. Myrtle flowers in the spring in either white or purple and is very impressive when in full flower. Pachysandra’s white flowers are less impressive but plentiful.

All of the evergreen groundcovers spread relatively quickly and will carpet an area with a dense mat of foliage. They will also suppress weed growth (although in my experience Myrtle can have a bit of an issue with grass growing up through it) and in time will require little or no maintenance.

MADE IN THE SHADE

As is true of just about any plant in shady situations, each of the three evergreen groundcovers just mentioned can have issues with biological afflictions. Pachysandra and Myrtle, for example, can be susceptible to periodic problems with fungal diseases that will cause unsightly curling of their leaves – problems that are readily treated. As a Euonymous, Wintercreeper commonly has issues with gall and scale.

Beyond that, a far bigger issue for me with all three of these plants is that they’re tremendous leaf-catchers. When leaves start falling from trees above these plantings in autumn, they get caught in every nook and cranny they can find, and the only efficient way to remove them is with a rake that very likely will pull out some of the groundcover as well. And you can’t just let well enough alone: If the leaves accumulate, they’ll form a mat that can smother the groundcover.

My recommendation is the obvious one: Avoid using these groundcovers under dense trees and shift gears toward use of a whole range of perennial groundcovers. (In doing so, I don’t take that word “groundcovers” too literally, because almost any plant can be considered a groundcover if it’s used that way.)

What I look for are perennials that don’t grow very tall, but I’m not terribly picky. So where Myrtle and Pachysandra top out at about six inches, with perennials and shrubs as groundcovers I tend to be more liberal and will even use Dwarf Forsythia, which grows to be about three feet tall. As I see it, the most important feature of whatever plants I decide to use is that they must all do well in the shade of dominant trees.

Forgive me, but I’m now going to discuss some plants that are familiar to me here in the northeast (Zone 6). I do so knowing that varieties of most (if not all) of them will survive (and even thrive) in climate zones throughout the 48 contiguous states.

This is one of those cases where my definition of ‘groundcover’ is clearly a bit broader than usual: Hakonechloa (also known as Japanese Forest Grass) doesn’t hug the ground, for example, but it spreads nicely, does well in filtered sun and can look great around waterfeatures, where its drooping structure is reminiscent of cascading waterfalls.

When I’m looking for a carefree, no-hassle groundcover for clients who just want to cover an area with whatever is available, I’ll choose Sweet Woodruff (gallium odoratum). It’s a soft, six-inch-tall perennial that spreads prolifically throughout shady and semi-shady areas and flowers in the spring with a wonderful fragrance (hence the “Sweet” part of its name).

To me, Woodruff is the best of the traditional groundcovers, mainly because it requires almost no care. We’ll plant it from two-inch cell packs at intervals of about eight inches on center and let it go. Within two years, it will fill an area completely, and it’s a great plant for barefoot walking, especially when it’s in flower in the spring.

As for dealing with falling leaves, I recommend to my clients that each fall, just as the leaves on the trees are changing, they should run a lawn mower over the Woodruff (or use a weed whip) to cut it to the ground. So when the leaves fall in abundance, all that’s needed is to rake them up. It’s so easy that never, ever has a client expressed any regret about our planting Woodruff.

PERENNIAL FAVORITES

There are, of course, many other perennials that perform wonderfully in the shade of large trees or copses of trees. With these possibilities, however, shade-tolerance is only one of the parameters I consider, with site moisture (wet or dry) being the other.

In most residential situations, dry is the norm. Indeed, one of the reasons grass fares poorly under canopies is that the trees hog all of the water, so I’ve spent a lot of time evaluating plants that will tolerate shady, dry environments. Although this list of plants is somewhat limited, there are nonetheless some stunning choices that will thrive, look good and do a fine job of keeping other, undesirable plants from taking hold.

My first choice among perennials for dry, shady spaces is Pulmonaria, a perennial that will actually behave like an evergreen in mild winters and features bright, white-polka-dotted leaves and small but spectacular flowers in both blue-purple and pink on the same plant. One of the best things about it is that Pulmonaria is among the first plants to flower in spring. The variety “Mrs. Moon” has large leaves and grows to about 24 inches wide, quickly filling an area.

Other Pulmonaria varieties, including “Bertram Anderson” and “Little Blue,” are beautiful plants worth consideration in dry-shady situations. I also use perennial Geraniums, one variety of which is native to northeastern forests and flowers early in spring. Geranium maculatum is a favorite of mine, and I also frequently use the “Rozanne” and “Dilys” varieties where there’s a bit more sun exposure.

Lamium maculatum is another variegated perennial that has the virtue of being able to withstand all sorts of abuse. It recovers very well when walked on or dug through – and flowers in either pink or white throughout the season, spreads quickly and brightens shaded areas with its mixed white-and-green leaves.

I also use Solomon’s Seal (polygonatum odoratum), another variegated plant that grows in a more upright fashion to a height of 18 to 24 inches. It takes a year or two to get going, but once it does, it will quickly fill an area and has white flowers hanging from its crescent-shaped form.

Damp or wet areas call for different plants, and my first choice is usually Astilbe. I’m partial to this perennial because of its stunning plumes of flowers. In addition, by mixing varieties and species, I can establish spaces that will have flowers from early June right through to the end of August – and even the spent flowers are spectacular.

(I grow seven Astilbe varieties for my own use and have a test plot of another 54 varieties. They come in colors ranging from white, pink and lavender to burgundy and red and span heights from 18 to above 48 inches. It is by far the best perennial there is in my book.)

Another perennial for damper locations is Hakonechloa (Japanese Forest Grass). This chartreuse weeping grass does a wonderful job of brightening shady areas, growing to about 18 inches before drooping like a cascading waterfall. It has such a pronounced “aquatic” aspect, in fact, that I often use Hakonechloa alongside waterfeatures to mimic falling water – or use it in waterless Asian gardens as part of dry falls.

A final plant to consider for damp shade is Japanese Primrose. This prolific spreader has white or fuchsia flowers atop eight- to ten-inch stalks and is a great companion to both Astilbe and Hakonechloa. In fact, I frequently mass these three plants together in sweeps to bring drama to shaded spaces.

This is just a brief sampling of what can be done as alternatives to the lawns that almost certainly will fail in deeply shaded areas. These groundcovers are all easy to work with, solve substantial design problems and offer clients stunning vistas that will make them forget all of the frustration they experienced through years of trying to make a lawn thrive where it simply couldn’t make the grade.

Bruce Zaretsky is president of Zaretsky and Associates, a landscape design/construction/consultation company in Rochester, N.Y. Nationally recognized for creative and inspiring residential landscapes, he also works with healthcare facilities, nursing homes and local municipalities in conceiving and installing healing and meditation gardens. You can reach him at [email protected].